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United States Patent | 5,111,340 |
Kashima ,   et al. | May 5, 1992 |
Laser light emitted from a light source is deflected in a predetermined direction by a rotary polygonal mirror to scan the surface of a photosensitive medium. A correction lens corrects the focal point of the laser light deflected by the rotary polygonal mirror. The correction lens is formed by cutting a circular lens along a plane off the optical axis thereof and removing a segment of shorter arc therefrom. The correction lens is held by a lens holder by way of being pressed by a pressing member both in the radial direction and in the direction of the optical axis thereof to the lens holder.
Inventors: | Kashima; Hiroyuki (Nagoya, JP); Kinoshita; Naohisa (Nagoya, JP) |
Assignee: | Brother Kogyo Kabushiki Kaisha (Nagoya, JP) |
Appl. No.: | 618730 |
Filed: | November 27, 1990 |
Jan 10, 1990[JP] | 2-3850 |
Current U.S. Class: | 359/819; 359/216; 359/820 |
Intern'l Class: | G02B 007/02 |
Field of Search: | 350/6.7,6.8,252,253,243,242,257,479,480,481,245,255,247 |
3904276 | Sep., 1975 | Whitaker et al. | 359/819. |
4303306 | Dec., 1981 | Ookawa | 359/819. |
4733945 | Mar., 1988 | Bacich | 359/820. |
4762395 | Aug., 1988 | Gordon et al. | 359/820. |
4850674 | Jul., 1989 | Hasselskog | 359/820. |
4854671 | Aug., 1989 | Hanke et al. | 359/819. |
Foreign Patent Documents | |||
26706 | Feb., 1984 | JP | 359/820. |
31915 | Feb., 1984 | JP | 359/820. |
230609 | Nov., 1985 | JP | 359/820. |
6446713 | Feb., 1989 | JP. |